A few days later, the mansion felt like a pressure cooker ready to blow.

Katsuki had barely slept. Every time he closed his eyes he saw Izuku’s fat pink pussy dripping down her thigh, heard her porn-star moans from the massage, tasted the ghost of her ice-cream-slick fingers in his mouth. His cock stayed semi-hard around the clock, leaking pre-cum into his boxers like a broken faucet.

Mina, sweet oblivious Mina, waddled into the living room that evening with a tray of popcorn and sparkling water, belly round and glowing under her maternity dress.

“Katsuki! Izuku! Family movie night tonight! No excuses!”

Izuku bounced in right behind her, already dressed for war.

“Yayyy! I love movie nights!”

She was wearing what could generously be called clothes: a tiny black crop top so cropped it ended just under her nipples — the bottom curves of her massive tits fully exposed, jiggling with every step. Paired with a microscopic pleated skirt in the same black fabric, so short that when she stood still you could see the shadow of her bare pussy lips peeking out. No bra. No panties. Just smooth white skin, hard pink nipples poking through the thin top, and that fat juicy ass barely contained.

Katsuki’s jaw clenched so hard he thought his teeth might crack.

“Sounds… great,” he forced out.

Mina clapped happily. “Izuku wants to sit in the middle so she can cuddle both of us! Isn’t that adorable?”

Katsuki’s stomach dropped. “Middle?”

Izuku beamed up at him, batting her lashes. “Please, kacchan? I get scared during movies sometimes… I need my big strong brother-in-law to protect me~”

He wanted to say no. Wanted to tell her to sit on the fucking floor. But Mina was already beaming, rubbing her belly.

“It’s perfect! Come on, Katsuki, don’t be grumpy.”

He nodded once, stiffly. “Fine.”

They settled on the massive sectional couch. Lights dimmed. Mina on one end, Izuku in the very center, Katsuki on the other side — trapped.

The romcom started — some cheesy thing about fake dating and stolen kisses. Izuku immediately curled into his side, giggling at every flirty line.

“Awww, look at them! So cute!”

Every giggle made her heavy tits bounce and squish against his arm. Soft, warm, nipples like little diamonds scraping his bicep through his thin t-shirt. Katsuki’s cock surged to full hardness in seconds, straining painfully against his sweatpants. He shifted, trying to hide the bulge.

Izuku noticed. Of course she did. She pressed closer, “accidentally” letting one fat tit mash fully against his chest.

“Kacchan, you’re so warm…” she whispered, breath hot on his neck.

He gritted his teeth. “Watch the movie.”

Then came the “surprise” horror moment — a cheap jump-scare in the middle of the romcom. Izuku squealed dramatically, throwing herself half into his lap.

“Eek! Kacchan, save me!”

Her thick thighs straddled one of his, fat ass landing right on his throbbing cock. The skirt rode up instantly — nothing between her dripping pussy and his clothed dick except the thin fabric of his sweats. He could feel how soaked she was. Hot, slick heat seeping through, coating his length.

Mina laughed softly from the other side.

“Aww, Izuku’s such a scaredy-cat! So cute. Katsuki, hold her tight, okay?”

Katsuki groaned low in his throat — half pain, half pleasure. Izuku’s ass was grinding now. Slow. Deliberate. Tiny rolls of her hips that dragged her swollen clit right along the ridge of his cock. Her wetness was obscene — he could hear the faint wet sounds every time she moved.

“Fuck…” he breathed, so quiet only she could hear.

Izuku whimpered cutely for Mina’s benefit.

“Kacchan… so scary…”

But her voice dropped to a filthy whisper against his ear.

“Your cock’s so fucking hard… feel how wet my little pussy is for you? Been dripping since I sat down…”

She rocked harder, grinding her bare cunt lips up and down his shaft through the pants. The head of his cock caught on her clit and she bit her lip to stifle a real moan.

Katsuki’s hands flexed on the couch cushions. He was going to snap. He could feel every puffy fold sliding over him, her slick soaking darker and darker into the grey fabric.

Mina yawned hugely.

“Mmm… these pregnancy hormones are killing me. I’m so sleepy already…”

Within minutes her breathing evened out. Head lolled against the armrest. Asleep.

Izuku didn’t hesitate.

She swung one leg over fully, straddling Katsuki’s lap now, skirt hiked up around her waist. Her bare, dripping pussy pressed flush against his rock-hard cock. She rolled her hips in slow, filthy circles, coating him completely.

“Fuck yes…” she moaned softly, voice pure slut. “Finally… been dying to ride this neglected dick.”

Katsuki’s head fell back against the couch. A low, broken groan ripped out of him.

“Izuku… we can’t…”

She leaned in, fat tits smashing against his chest, hard nipples dragging over his shirt.

“Can’t what, kacchan? Can’t feel how tight and wet your little sister-in-law’s cunt is? How bad it’s clenching for your big cock?”

She ground down harder, pussy lips spreading wide around the thick ridge of him. Her clit throbbed against the head every time she rolled forward.

“Mina hasn’t touched this poor thing in months… look how fucking angry it is. Leaking for me. Begging to stretch my slutty little holes.”

Katsuki’s hands shot to her hips — not to stop her, but to grip hard, fingers digging into soft flesh.

“Goddamn it… you’re soaked…”

“Mhm,” she purred, rocking faster. “Been fingering myself every night thinking about you. Imagining you finally snapping and fucking me raw while mina sleeps. You want that, don’t you? Want to shove this fat cock in my tight pussy and breed me like the whore I am?”

He bucked up involuntarily, grinding back against her. The wet slide was obscene — her juices dripping down his balls now, soaking through everything.

“Fuck… Izuku…”

She reached down, yanked her tiny skirt up higher, flashing her puffy, glistening pussy fully. Pink and swollen, clit throbbing visibly, lips parted and dripping. She spread herself with two fingers, showing him how her hole clenched around nothing.

“Look at it, kacchan… so empty without you. Bet it would suck you in so deep… milk every drop out of these heavy balls.”

She ground down again, harder, faster. The friction was perfect — her slick cunt gliding over his clothed cock like she was trying to fuck him through the fabric.

“Gonna make you cum in your pants like a desperate teenager… then maybe next time I’ll let you actually fuck me. Fill me up while Mina snores right there.”

Katsuki was panting now, hips jerking up to meet her. His cock throbbed violently — so close. The wet heat, her filthy words, the sight of her spread pussy grinding on him — it was too much.

“I’m gonna—”

Izuku suddenly lifted off him. Completely.

She stood up, skirt falling back (barely) into place, pussy still glistening on her inner thighs.

Katsuki groaned — loud, angry, desperate. His cock jerked painfully in his soaked sweats, denied at the edge.

“Fuck! Izuku—!”

She dropped to her knees on the floor between his spread legs, one hand sliding up his thigh to palm his throbbing length through the fabric. She squeezed hard, thumb rubbing over the wet head.

“Shhh, kacchan…” she whispered, eyes wicked and sparkling. “Mina’s not using this big, fat cock anymore… can I?”

She leaned in, hot breath ghosting over the soaked bulge.

“Can your slutty little sister-in-law take care of it for her? Suck it… ride it… let you fuck my tight holes until you forget her name?”

Katsuki’s head thumped back against the couch. A tortured moan tore out of him.

“Jesus… fuck…”

Izuku just smiled — slow, filthy, victorious — and gave his cock one last slow squeeze.